Dien Bien Phu (sometimes Dienbienphu) is a town in northwest Vietnam, famous as the site of the Battle of Dien Bien Phu.

By 1954, Vietnamese nationalists under the leadership of Hồ Chí Minh had been waging a guerrilla war against the French colonial government of what was then French Indochina since 1946. The Vietnamese insurrection was receiving significant military aid from the Chinese Communist Party, which overthrew the Chinese Nationalist Government with Soviet aid in 1949. The United States, which eventually became committed to stopping the spread of communism as per the containment doctrine, began financing 80% of the French war effort.

Dien Bien Phu was intended to be a French bridgehead in the mountainous north of the country, which had long been a stronghold for the Viet Minh. However, Vietnamese general Võ Nguyên Giáp was able to quickly assemble a large force, including a minimum of sixty thousand men and a large amount of heavy weaponry. The French troops, outnumbered five to one and cut off from supplies, finally surrendered after a grueling two-month siege.

The battle proved decisive in ending support for an already unpopular war, leading to a treaty and the division of French Indochina into Cambodia, Laos, and North and South Vietnam. Ultimately, the outcome of the war would provoke the similar Vietnam War a decade later.